How Many Calories Should You Actually Eat to Lose Fat?

This is the question I get asked more than almost any other, and the honest answer is: it depends — but not in the vague, unhelpful way that sounds. There's a real, calculable starting point, and most people either overcomplicate it or guess wildly. Here's how to actually work it out.

The Basic Principle (It's Simpler Than the Internet Makes It Look)

Fat loss happens when you consistently eat fewer calories than your body burns — a calorie deficit. That's it, biologically. Where people go wrong isn't the principle, it's estimating the numbers and — more often — sticking to the plan for long enough to see it work.

Step 1: Find Your Maintenance Calories

Before you can create a deficit, you need a rough idea of what you currently eat to maintain your weight. A simple starting formula: bodyweight (kg) × 24–26 gives a rough daily maintenance estimate for someone with a fairly sedentary desk job and moderate activity. It's an estimate, not gospel — but it's a real starting point, not a guess.

Step 2: Apply a Sensible Deficit

A deficit of roughly 300–500 calories below maintenance is the sweet spot for most busy professionals — enough to see consistent progress without the extreme hunger and energy crashes that come with more aggressive cuts (which usually backfire within a few weeks anyway).

Why not go bigger for faster results? A larger deficit sounds appealing, but in practice it tends to increase muscle loss alongside fat loss, tank your energy for training and work, and make the plan far harder to sustain — which means it usually gets abandoned before real results show up. Slower and sustained beats fast and abandoned, every time.

Step 3: Prioritise Protein Within That Number

Of your total calories, protein matters disproportionately — it preserves muscle while you're in a deficit (so the weight you lose is more fat, less muscle) and it's the most satiating macronutrient, which makes the deficit itself easier to stick to. A rough target of 1.6–2.2g of protein per kg of bodyweight is a solid range for most people actively losing fat.

Why the "Right" Number Still Needs Adjusting

Your actual number is a starting estimate, not a fixed target carved in stone. If the scale hasn't moved in 2–3 weeks despite consistency, the number needs a small adjustment down. If you're constantly starving, exhausted, or your training is suffering, it might need to come up slightly, or you need more diet breaks built in. This is exactly why I review it with clients weekly rather than handing over one number on day one and hoping it holds for 12 weeks.

What This Looks Like Without Obsessive Tracking

You don't need to weigh every gram of food for this to work. Most of my clients start with a rough calorie range and a simple protein target, adjusted based on real weekly progress — not a rigid number they have to hit perfectly every single day. Consistency at "roughly right" beats perfection you can't sustain.

Common Mistakes I See

• Guessing a number with no real basis, then wondering why nothing changes

• Cutting too aggressively, burning out within three weeks

• Ignoring protein entirely while hitting a "calorie number" — losing muscle along with fat

• Never adjusting the number as their body and results change over 12 weeks

Want Your Actual Number, Not a Generic Estimate?

A formula gets you a starting point — a coach gets you the number that's actually right for your body, your training, and your schedule, adjusted weekly as real data comes in. If you want that instead of guesswork, let's talk.

[Book a free consultation →] https://syp-fitness.co.uk (+44 7572 002261)